Mold and method for forming a pressurized fluid chamber

ABSTRACT

A fluid chamber (20) for a shoe may be formed using pressure channels (190) in a forming mold (100A), eliminating the need to insert a nozzle or needles into the chamber for inflation. A fluid chamber so formed may have a smaller seal area than a chamber formed using an inflation needle, making the chamber more visually pleasing. Apparatus and methods for forming a fluid chamber in this fashion are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 365 toPCT/US2016/067259, filed on Dec. 16, 2016, entitled “Mold and Method forForming a Pressurized Fluid Chamber,” which claims priority to U.S. App.No. 62/268,798 filed on Dec. 17, 2015, entitled “Fluid Chamber for aShoe,” the entirety of the aforementioned applications are incorporatedby reference herein.

BACKGROUND OF THE INVENTION

Shoes may have fluid-filled chambers in or near the sole of the shoe.The fluid-filled chambers may provide cushioning and/or impactprotection. Such chambers have been incorporated into athletic and dressshoes. Some shoe designs have included visible air or gel chambers,which may help a consumer select a shoe with a fluid-filled chamber orchambers. If the chambers are hidden, it may be difficult for a consumerwho likes the fluid-filled chambers to distinguish shoes having thefluid-filled chambers from shoes which do not have the fluid-filledchambers. Visible fluid-filled chambers may also be aestheticallypleasing, providing an interesting visual aspect to a shoe. Accordingly,it may be desirable to make at least a portion of a fluid-filled chambervisible in a finished shoe.

The chambers may be formed by inflating a space between two or morelayers of membrane or film. The membrane or film may be formed intochamber, and a needle inserted into the chamber to pressurize thechamber. The hole through which the needle was inserted may then besealed as the needle is withdrawn, as by heat welding.

BRIEF DESCRIPTION OF THE DRAWING

The detailed description below makes reference to the attached drawingfigures, wherein:

FIG. 1 is an exemplary shoe;

FIG. 2 is an exemplary cavity forming mold for a shoe sole;

FIG. 3 is an exemplary mold feature for forming a chamber;

FIG. 4 is an exemplary mold and cap plate;

FIG. 5 is a top view of an exemplary cap plate;

FIG. 6 is a perspective view of an exemplary seaming apparatus; and

FIG. 7 is a flowchart for a process for forming a fluid-filled chamber.

DETAILED DESCRIPTION OF THE INVENTION

While processes of forming a membrane or film into a pocket, inserting aneedle into the pocket to pressurize the pocket, and then sealing thepocket around the needle are effective for creating functionalfluid-filled chambers, these processes often leave a large seam aroundthe needle entry point. The seam may be visually distinct from theremainder of the chamber, and may be ugly or may look out of place, likethe chamber was not formed properly. The inventors have observed thatthere remains a need for a chamber which has a more uniform appearance,so that the seam on the chamber is less of a constraint in aestheticshoe design. The inventors have also observed that there remains a needfor an apparatus and method for forming a chamber having a more uniformappearance.

In some aspects, this disclosure generally relates to a fluid-filledchamber for a shoe. The fluid-filled chamber may be formed using athermoforming mold. Pliable materials such as, for example,thermoplastics can be used to form the fluid-filled chambers of thepresent disclosure. Various processes can be used to form (i.e., shape)the materials, such as vacuum forming and/or thermal forming. The vacuumforming of the material can be conducted by placing the pliable materialin the mold, then applying vacuum and/or heat to the material. Duringthe vacuum forming, a small hole may be formed in an area of the pliablematerial defining a chamber. Pressurized fluid can be delivered into thechamber through the hole formed in the pliable material without need toinsert a needle or nozzle into the chamber. A seaming apparatus may besituated near the hole through which the pressurized fluid is delivered.During or just after the delivery of the pressurized fluid, the seamingapparatus may close the small hole. Because the hole is small andbecause the seam does not need to be formed around another structure,such as a needle or nozzle, the seam may be smaller than the seams inconventional chamber formation. This may provide a chamber with a moreuniform appearance. The more uniform appearance may make the chambersuitable for shoe designs where large portions of the surface area ofthe chamber are visible in the finished shoe. The formation process mayalso facilitate the placement of the chamber seam on an interior-facingportion of the chamber, further increasing the surface area of thechamber suitable for visual presentation.

In some aspects, the disclosure relates to a mold for forming apressurized fluid chamber. The mold may comprise a generally planarregion, and a dome-like depression within the planar region. The moldmay further comprise a compression area bounding the generally planarregion and protruding upwardly from a front surface of the mold suchthat the compression area is raised relative to the generally planarregion. The mold may further comprise a channel through at least two ofthe generally planar region, the dome-like depression, and thecompression area. The channel may be in fluid communication with an areaof the mold beyond the compression area. The channel may be disposedthrough all three of the generally planar region, the dome-likedepression, and the compression area. In either embodiment of thechannel, the dome-like depression may comprise an oculus that opensthrough a rear-facing side of the mold to an exterior of the mold. Thedome-like depression may have a diameter between 4 mm and 8 mm. Theoculus may have a diameter between 2.7 mm and 5.5 mm.

In some aspects, the disclosure relates to a system for inflating athermoformed fluid chamber. The system may comprise a mold. The mold maycomprise a cavity forming plate and a cap plate. The cavity formingplate may comprise a relief area. The cavity forming plate may comprisean opening within the relief area. The opening may be in fluidcommunication with an exterior of the mold. The cavity forming plate maycomprise a compression area. The compression area may bound the reliefarea and protrude upwardly from a front surface of the mold such thatthe compression area is raised relative to the relief area. The cavityforming plate may comprise one or more venting apertures outside thecompression area. The cap plate may comprise an aperture in fluidcommunication with the opening of the cavity forming plate. The capplate may further comprise raised regions corresponding to the one ormore venting apertures in the cavity forming plate and protrudingupwardly from a front surface of the cap plate. The cap plate mayfurther comprise one or more pressure channels, the pressure channels influid communication with the aperture. The system may further comprise aseaming apparatus. The seaming apparatus may be situated external to themold.

In any embodiment of the system, the one or more pressure channels mayalternately deliver vacuum and positive pressure. The system may furthercomprise an air pressure delivery tube. The air pressure delivery tubemay be integral to the seaming apparatus. The seaming apparatus maycompletely surround the circumference of the air pressure delivery tube.The seaming apparatus may comprise two or more welding heads.

In any of these embodiments, the cavity forming plate may furthercomprise a partial opening through at least a portion of at least oneedge of the relief area and compression area. The partial opening may bein fluid communication with an area of the mold outside the boundary ofthe compression area. In any of these embodiments, the seaming apparatusmay employ energy selected from heat, ultrasound, and radio frequency.In any of these embodiments, the air pressure delivery tube may deliverfluid under a pressure between 1 and 50 psig. In any of theseembodiments, the relief area may be generally planar. In any of theseembodiments, the opening may be concave relative to the relief area. Inany of these embodiments, the opening may be round.

In some aspects, the disclosure relates to a method for inflating athermoformed chamber. The method may comprise applying a vacuum to aconfined portion of a pliable material until the material ruptures toform an opening in the material. The method may comprise delivering apressurized fluid to the pliable material through the opening. Themethod may comprise sealing the opening while the pliable material ispressurized. The method may be performed without inserting anythingother than pressurized fluid into the opening. The pliable material maybe thermoplastic polyurethane. The pliable material may be pliable atroom temperature. The method, in any of these embodiments, may furthercomprise thermoforming the pliable material. The pliable material may bepliable during some portion of the thermoforming process.

In any of these embodiments, the opening in the pliable material may begreater than 0 mm and less than approximately 3.5 mm in maximumdimension. In any of these embodiments, the pressurized fluid may be agas. The pressurized fluid may be selected from air, nitrogen,octafluorapropane, hexafluroethane, sulfur hexafluoride, andcombinations thereof. In any of these embodiments, the pliable materialmay form a chamber around the opening. The chamber may be inflated andpressurized by delivering the pressurized fluid to the pliable materialthrough the opening. The chamber may be at least partially inflatedprior to delivering the pressurized fluid to the pliable materialthrough the opening. In any of these embodiments, the chamber may bepressurized to about 1-51 psig. In any of these embodiments, the openingmay be sealed using heat stack, ultrasound, or radio frequency seaming.The sealing may begin while the pressurized fluid is delivered into thepliable material. The sealing may be finished concurrent with completionof the delivery of the pressurized fluid. In any of these embodiments,the pliable material may have a single-ply thickness between 1 and 3 mm.

In some aspects, the present disclosure relates to a component for ashoe made according to any of these methods. The component for a shoemay form all or a part of the sole of the shoe. The component may be aninsert between the interior of the shoe and the sole of the shoe. In anyof these embodiments, the shoe may comprise a window through which thecomponent is visible when the shoe is fully assembled. In any of theseembodiments, substantially all exterior-facing surfaces of the componentmay be visible through the window when the shoe is fully assembled.Substantially all of the exterior-facing surfaces of the component maybe visible through the window when the shoe is fully assembled, exceptfor the bottom-facing surface.

In any of these embodiments, the component for a shoe may have a sealarea created by sealing the opening. The seal area may be positioned onthe component such that the seal area is not visible when the shoe isfully assembled. The seal area may be positioned on an internal-facingsurface of the component when the shoe is fully assembled. The seal areamay be covered by another shoe structure when the shoe is fullyassembled. The seal area may be greater than 0 mm and less thanapproximately 3.5 mm in maximum dimension.

Additional variations, objects, advantages, and novel features of thedisclosure will be set forth in part in the description which follows,and in part will become apparent to those skilled in the art uponexamination of the following, or may be learned by practice of thedisclosure.

As used in this disclosure, “any of” means any combination of therecited claims and/or disclosed elements, including any combination of 2or more of the recited claims or elements, and also including any one ofthe recited claims or elements. As a non-limiting example, a claimreciting a method according to any of claims 100 to 105 includes acombination of the claimed method elements with the claimed methodelements of any of claims 100-105 individually, or with anysubcombination of claims 100-105, or with all of claims 100-105.

As used in this disclosure, “fluid” refers to a gas, liquid, gel, orcombination thereof, suitable for use in a shoe chamber for cushioningor impact protection. Exemplary fluids include, without limitation, air,nitrogen, octafluorapropane, hexafluorethane, sulfur hexafluoride, andcombinations thereof.

As used in this disclosure, “vacuum” refers to a controlled reduction inlocal air pressure relative to atmospheric pressure at the sameelevation and temperature. As used in this disclosure, “positivepressure” refers to a controlled increase in the pressure of asubstance, such as a fluid, relative to the pressure of the fluid in anopen container (unrestricted volume) at the same elevation andtemperature.

As used in this disclosure, “front” or “internal”, in relation to amold, refers to the side or face of the mold that is or includes thematerial-contact portion of the mold, e.g., the surface to which themolded material is molded, which may also be called the forming cavity.As used in this disclosure, “rear”, “back” or “external”, in relation toa mold, refers to the opposite side or face of a mold or forming platefrom the internal side or face. The external portion of a mold or cavityforming plate may be connected to other apparatus related to the formingprocess, such as heaters, sources of pressure, sources of vacuum,positioning machinery, etc. A forming cavity may be open—there may be nomachine or tool cover for the forming cavity during the formingprocess—or enclosed—either capped by another tool or plate or enclosedwithin a larger machine during at least a portion of the formingprocess.

FIG. 1 is a side view of an exemplary shoe 10 having visible,fluid-filled chambers 20 in or near the sole 30 of the shoe 10. Shoe 10also has an upper 40, including a tongue 50 and closure 60. Asillustrated, closure 60 comprises shoelaces looped through eyelets onopposing sides of tongue 50, however, any suitable closure method couldbe used, including, without limitation, stretch materials, hook-and-loopfasteners, or other mechanical fasteners, such as snaps, buttons,zippers, etc. Between sole 30 and upper 40, on the inside of the shoe,there may be additional elements (not shown) for comfort and/oradditional cushioning, such as a sock liner and/or foam padding.Exemplary shoe 10 has the general shape of a running or athletic shoe,however, the chambers disclosed could be used in any variety offootwear, including slippers, dance shoes, casual shoes, dress shoes,boots, and the like. Of course, different varieties of athletic shoesmight also include chambers as disclosed, including, without limitation,running shoes, basketball shoes, cross-training shoes, fitness shoes,ski boots, skateboarding shoes, and the like.

FIG. 2 shows an exemplary mold 100 for forming a shoe sole 30 or portionthereof comprising a fluid-filled chamber 20. Mold 100 comprises acavity forming plate 105 on an internal surface of mold 100. As shown inFIG. 2, cavity forming plate 105 has a chamber-forming feature 110positioned generally near the heel portion of the sole, however,chamber-forming feature 110 can be positioned in any desirable location.A single, continuous chamber-forming feature 110 may be used, or two ormore discrete chamber-forming features 110, for example, between 2 and16 chamber-forming features, or between 2 and 8 chamber-formingfeatures, or between 2 and 6 chamber-forming features, may be used. Anodd number of chamber-forming features may be used. The chamber-formingfeatures, if more than one chamber-forming feature is used, may be ofthe same or similar size and shape, or may be of different sizes andshapes. For example, as shown in FIG. 1, chambers 20 near the toe 70 ofthe shoe may be somewhat smaller than chambers 20 near the heel 80 ofthe shoe.

FIG. 3 shows a detailed view of the chamber-forming feature 110. Chamberforming feature 110 presents a generally planar region 120, and adome-like depression 130 within generally planar region 120. Thegenerally planar region 120 need not be strictly planar, however, itshould provide a small, localized area of limited shape complexity tofacilitate the formation of a small hole in a material within the mold,as described below. Instead of generally planar region 120, other shapesor topography may be suitable to serve as a relief area, depending onthe materials and processes (e.g., thermoforming, vacuum forming,casting, etc.) used. Generally planar region 120 may be planar withintypical industry tolerances for machining the mold 100. Generally planarregion 120 may be bounded by a compression area 140. Compression area140 may protrude upwardly from a front surface 150 of mold 100, and maybe raised relative to generally planar region 120. As shown in FIG. 3,generally planar region 120 may also be raised relative to front surface150 of mold 100. A channel 160 may run through generally planar region120, dome-like depression 130, and compression area 140. In someembodiments, channel 160 may run through only one of generally planarregion 120, and compression area 140, for example, through generallyplanar region 120 and dome-like depression 130, or through compressionarea 140 and dome-like depression 130. Channel 160 may provide fluidcommunication between the chamber-forming feature 110 of mold 100 and avacuum and/or pressure source exterior to mold 100, as described below.

Dome-like depression 130 may be circular or oval or other shapes. Arounded shape may be preferred, but is not required. Dome-likedepression 130 may comprise an oculus 170 that opens to an exteriorsurface (not shown) of mold 100. The diameter of the oculus, if round,may be between 2 mm and 8 mm, or between 2.7 mm and 5.5 mm, inclusive ofendpoints. The diameter of the oculus may be 2 mm or greater and lessthan the maximum diameter of the dome-like depression. If the opening inthe depression is not round, the opening may be of a similar area.

Mold 100 a may comprise a cavity forming plate 105 a and a cap plate180, as shown in FIG. 4. As shown in FIG. 4, mold 100 a may comprisemultiple chamber-forming features 110 a, however, a cap plate may alsobe used with a singular mold or with a chamber-forming feature 110incorporated into a mold 100 for part of all of a sole 30, as shown inFIG. 2, an entire shoe, or other component(s) of a shoe. Cap plate 180may fit against the exterior surface of cavity forming plate 105 a. Capplate 180 may have pressure channels 190, as shown in FIG. 5. Twopressure channels 190 are shown. A single pressure channel 190 ormultiple pressure channels 190, such as three, four, five, six, seven,or eight pressure channels 190, may be used. A unique pressure channel190 may be used for each chamber-forming feature 110 a in correspondingmold 100 a. Pressure channels 190 may serve as vacuum delivery tubes forforming an opening in a material inside the mold, as described below.Pressure channels 190 may be able to alternately deliver vacuum andpositive pressure. For example, pressure channels 190 may be connectedto a pump capable of generating positive and negative pressure, or mayhave connections to both a vacuum pump and a pressure pump.

Chamber-forming feature 110 a, similar to chamber-forming feature 110but oriented differently in mold 100 a, may comprise a relief area 200and an opening 210 within relief area 200. Relief area 200 may begenerally planar. Opening 210 may be in fluid communication with theexterior of mold 110 a (not shown). Chamber-forming feature 110 a mayfurther comprise a compression area 220, bounding relief area 200 andprotruding upwardly from front surface 230 of mold 110 a. Compressionarea 220 may be raised relative to relief area 200, which may itself beraised relative to front surface 230 of mold 110 a. Opening 210 may beconcave relative to relief area 200. Opening 210 may be positionedsolely in the relief area 200, and/or may extend through at least aportion of the compression area 220. In relation to compression area220, opening 210 may be partial, meaning that opening 210 does notextend through the entire depth of the structure as raised above thesurface of mold 110 a. If the opening 210 is partial and runs throughcompression area 220 there may be a “bridge” of compression area 220that runs over or under opening 210. Mold 110 a may further comprise oneor more venting apertures outside compression area 220, as are known inconventional vacuum-forming and blowing processes. Opening 210 isdistinct from and does not share the function of a venting aperture orventing apertures, if venting apertures are used.

Cap plate 180 may be fitted against mold 100 a such that pressurechannel 190 is in fluid communication with opening 210 in cavity formingplate 105 a of mold 100 a when cap plate 180 is situated against theexterior surface of cavity forming plate 105 a. Cap plate 180 maycomprise raised regions (not shown) corresponding to one or more ventingapertures in cavity forming plate 105 a. The raised regions may protrudeupwardly from a front surface of cap plate 180, where front surface ofcap plate 180 is the surface that mates with the rear or exteriorsurface of mold 100 a. Cap plate 180 is presented as a unitary plate,however, if more than one pressure channel 190 is used, multiple,distinct cap plates 180 may also be used. For example, there may be aseparate cap plate 180 for each pressure channel 190, and/or for eachchamber-forming feature 110 a, or for a subset of pressure channels 190and/or chamber-forming features 110 a.

A system for forming a fluid-filled chamber may have at least one mold110 a, with mold 110 a having at least one cavity forming plate 105 a,at least one cap plate 180, and, as shown in FIG. 6, a pressure deliveryand seaming tube 250. Pressure delivery and seaming tube 250 may bepositioned on an opposite surface of a formed part 280 relative tocavity-forming plate 105 a (not shown in FIG. 6), proximate a hole informed part 280 corresponding in position to the position of oculus 170or opening 210. Pressure delivery and seaming tube 250 includes an airsupply port 240 and a seaming head 260. These are illustrated in FIG. 6as a unitary structure, however, air supply port 240 and seaming head260 could also be separate structures.

Air supply port 240 may be in fluid communication with an opening 285 ina part 280 formed using chamber-forming feature 110 a from the frontsurface of the formed part (i.e., the portion of formed part 280 thatwas facing away from mold 100 a during forming). In some embodiments,air supply port 240 may be moved into and out of fluid communicationwith opening 285 in formed part 280 during the course of the moldingprocess. For example, air supply port 240 may be mounted on areciprocating or multi-axis arm that moves air supply port 240 duringthe molding process. Alternately, formed part 280 may be moved to airsupply port 240, which may be distinct from mold 110 a. For example, airsupply port 240 may be a component of a separate machine and/or aseparate manufacturing station from mold 110 a. If formed part 280 ismoved to air supply port 240, formed part 280 may be removed from mold110 a prior to or while moving formed part 280.

Air supply port 240 may serve as a pressure delivery tube. Air supplyport 240 or a pressure delivery tube are distinguishable from needles ornozzles used conventionally to fill fluid-filled chambers for shoes atleast in part because the air supply port or pressure delivery tube donot need to enter the chamber to pressurize it.

As shown in FIG. 6, seaming head 260 is integral with air supply port240, and therefore has the same proximity to formed part 280 as airsupply port 240. In other embodiments, seaming head 260 may be aseparate structure which moves independently of air supply port 240. Forexample, seaming head 260 may be a heat-welding surface that is broughtinto proximity with formed part 280 only at or near the time to seal anopening 285 in formed part 280, and seaming head 260 may be relativelyremote from formed part 280 during other parts of the process. Seaminghead 260 may be a radio frequency electrode or ultrasound source whichcan be quickly and easily activated and deactivated during the moldingprocess, in which case there might be no need to change the proximity ofseaming head 260 to formed part 280 during the process. As shown in FIG.6, seaming head 260 may have a contact perimeter 270 that is slightlylarger than air supply port 240. As also shown in FIG. 6, it is notnecessary for seaming head 260 to have the same shape or generalconfiguration as air supply port 240. Seaming head 260 may have the samegeneral shape or size of relief area 200, within compression area 220.Seaming head 260 may have a contact perimeter that is larger than airsupply port 240 and smaller than the outer bound of compression area220. The perimeter of seaming head 260 is described as a contactperimeter, however, it will be understood by one of skill in the artthat it may not be necessary for seaming head 260 to actually contactformed part 280 in order to form a functional seal of opening 285 informed part 280. Seaming head 260 may provide a continuous contactperimeter, or may have small gaps or discontinuities in the perimeter ifthe material being seamed and the seaming energy source used permit theformation of a complete, functional seal without a continuous contactperimeter. For example, it may be possible to achieve a functional,continuous heat seal without applying heat along the entire seal—heatapplied to discrete points near the seal may be sufficient to form acontinuous seal. Two or more seaming heads 260 may be used, and if twoor more seaming heads 260 are used, they may be incorporated into aunitary structure (e.g., built into an seaming tube, with or without airsupply port 240), or may be discrete structures.

A fluid-filled chamber 20 may be formed using a pliable material, asshown in FIG. 7. The pliable material may be thermoplastic, orthermoset, i.e., the material may be pliable only under certainconditions, such as in a certain temperature range. The pliable materialmay be introduced into a mold 100 or 100 a such that at least part ofthe material covers oculus 170 or opening 210 in mold 100 or 100 a, asrepresented in step 290. Vacuum may be applied to generate air flowinside mold 100 or 100 a through channel 160 toward the exterior of mold100 or 100 a, through the pliable material. Oculus 170 or opening 210may focus the air flow to create a relatively high speed flow against arelatively small area of the pliable material until the pliable materialruptures, as represented in step 300. The area of the pliable materialmost affected by the vacuum may be influenced by the size of oculus 170or opening 210. The rate and volume of air flow required to rupture thematerial will depend upon the particular material and conditions used.The pliable material may be heated before or while it is ruptured inthis way, e.g., by heating the material before putting it in the mold,heating the mold, providing a heat source adjacent to the materialand/or the mold, or combinations thereof. The vacuum applied to rupturethe material may be greater in magnitude than the vacuum used to holdthe material against the mold during the initial forming process.

Once the material is ruptured, pressurized fluid may be deliveredthrough channel 160 and oculus 170 or opening 210 into the material, asshown in step 310. The material may have been formed into a chamber orinflated before the pressurized fluid is introduced, or the chamber maybe formed or formation of the chamber may be completed by thepressurized fluid pushing the material against the interior of cavityforming plate 105 or 105 a. The material may also be pushed outwardly,away from the interior of cavity forming plate 105 or 105 a, forming aninflated fluid-filled chamber.

Pressure channels 190 may serve as a vacuum delivery tube. Pressurechannels 190 may also provide a vacuum greater in magnitude than thevacuum used, if any, to form or begin forming the part (i.e., a pressurelower than the forming vacuum pressure, or a fluid flow rate greaterthan that used to form the part). The air flow generated throughpressure channels 190 may be greater than 0 Liters/second (L/sec) andless than about 6 L/sec. Higher air flow rates may be desirable withsome processes, systems, and/or materials. The process of applyingvacuum to rupture the material inside the mold, alone or in combinationwith the introduction of pressurized fluid, may alter the configurationof the material inside the mold to give the final shape to the moldedpart. That is, the part may be initially or partially formed byconventional thermoforming or vacuum forming, and the forming may becompleted by the application of vacuum and/or pressure to the chamberportion of the molded material. Pressure channels 190 may be configuredto further deliver fluid under positive pressure, e.g., to help expandand/or at least partially inflate the chamber portion.

Pressurized fluid may be delivered at a pressure and/or flow rate thatis insufficient to rupture the pliable material again. Depending uponthe material used, it may be desirable to cool the material and/or themold, if either was heated during the forming process, before, while, orafter the pressurized fluid is delivered. The pressurized fluid itselfmay cool or contribute to the cooling of the material and/or the mold.This cooling may be relative to an initial heated state, and need notnecessarily cool the material to or below room temperature.

Pressurized fluid may be added until a desired pressure and/or volume isachieved inside the chamber. The desired pressure and/or volume willvary depending on the design of the chamber, which will in turn varydepending on the aesthetic design and function of the shoe for which thechamber is intended. The desired chamber pressure may range from 1-51pounds per square inch gauge (psig) (approximately 6 kPa to 352 kPa),inclusive of endpoints. When the desired pressure and/or volume isachieved or nearly achieved, the opening is sealed, as shown in step320.

In some embodiments, an initial pressurization step is used as part ofthe molding process, to form a pre-inflated chamber. Once thepre-inflated chamber is formed, formed part 280 may be moved to aseparate manufacturing station, with or without maintaining pressure inthe pre-inflated chamber, to perform the final pressurization of thechamber and/or seal opening 285 in formed part 280. Alternately, thepre-inflated chamber may be kept at pressure and sealed, orre-pressurized and sealed in situ. The sealing may begin before thedesired pressure or volume is reached, or sealing may begin when thedesired pressure or volume is reached, or sealing may begin after thedesired pressure or volume is reached. That is, sealing may begin whilethe chamber is still being pressurized or filled, or sealing may beginwhile the chamber is at the desired pressure or volume. The sealingprocess may be finished concurrent with completion of the delivery ofthe pressurized fluid.

Because of the localized shape of the pliable material (e.g., havingconformed to dome-like depression 130 and generally planar area 120),pressurized fluid can be introduced into the chamber through channel160, or even after formed part 280 has been removed from mold 100,without introducing a needle, nozzle, or other object into the chamber.This means that the rupture in the pliable material can be quite small,from a pinhole just greater than 0 mm to less than approximately 3.5 mmin maximum dimension. As a result, the seam area where the chamber isclosed after the pressurized fluid is introduced can be much smallerthan the seam generated in conventional processes, which typicallyinsert a nozzle into the chamber for pressurization. Further, the seamcan be positioned on a surface that will ultimately face into the shoe,e.g., abutting the inside of the shoe, where a foot would rest when theshoe is worn, and where the seam may be covered by other structures,such as padding, cushioning, a sock liner, etc. In this way, the seammay be both small enough and positioned such that it is not visible inthe assembled shoe, even if a significant portion of the chamber isvisible. Alternatively, the seam may be positioned against struts, anouter sole, or other structures in the shoe to make the seam lessvisible, less noticeable, or invisible in the assembled shoe. Thispositioning is simplified by the reduced size of the seam relative toconventional fluid-filled chambers for shoes.

The pliable material may be a film or membrane. The film or membrane mayhave a single ply thickness between about 1 and 3 mm, inclusive ofendpoints. An exemplary material suitable for forming the chamber isthermoplastic polyurethane (TPU).

In some aspects, a fluid-filled chamber may be formed using the mold,apparatus, and/or methods described herein. The fluid-filled chamber maybe a component for a shoe. The component may comprise part of the soleof a shoe. The component may be the entire sole for a shoe. Thecomponent may be an insert between the interior of the shoe (e.g., wherea foot would reside when the shoe is worn) and the outsole of the shoe(e.g., the portion of the shoe that contacts the ground when worn). Ashoe may comprise a window. The fluid-filled chamber component may be atleast partially visible when the shoe is assembled. The fluid-filledchamber component may be visible through the window. The window may be astructure comprising a translucent or transparent material, or may be adiscontinuity in the structure of the shoe. The window may be an openingin the shoe through which underlying structure is visible.

The fluid-filled chamber component may have exterior-facing andinterior-facing surfaces when positioned within a shoe. Theexterior-facing surfaces face away from the interior of the shoe, whilethe interior-facing surfaces face into the shoe. Typically, thevisibility of interior-facing surfaces is obstructed by other shoestructures, although it is possible for an interior-facing surface to bevisible in an assembled shoe, particularly, but not exclusively, whenthe shoe is not being worn. Substantially all exterior-facing surfacesof the fluid-filled chamber, such as 75% or more, or 85% or more, or 95%or more, of the exterior-facing surfaces of the fluid-filled chamber maybe visible when the shoe is fully assembled. Substantially allexterior-facing surfaces of the fluid-filled chamber component may bevisible through a window when the shoe is fully assembled. Substantiallyall exterior-facing surfaces of the fluid-filled chamber component maybe visible, through a window or otherwise, when the shoe is fullyassembled, except for the bottom-facing surface. Stated differently, theground-contact portion of the shoe may obscure the visibility of thefluid-filled chamber component. The ground-contact portion of the shoecould also include windows or discontinuities through which part of thefluid-filled chamber component may be visible. If a shoe comprisesmultiple fluid-filled chamber components, different fluid-filled chambercomponents may have different visible portions, in magnitude, position,and/or perspective.

A seal area is created by sealing an opening used to create afluid-filled chamber component. The seal area may be visually distinctfrom the chamber material outside the seal area. The seal area may bepositioned on the component such that the seal area is not visible whenthe shoe is fully assembled. Alternately or additionally, the componentmay be positioned within the shoe such that the seal area is not visiblewhen the shoe is fully assembled. For example, the seal area may bepositioned on an internal-facing surface of the component when the shoeis fully assembled. The seal area may be positioned within the shoe suchthat the seal area is covered by another shoe structure when the shoe isfully assembled, whether the seal-area is exterior-facing orinterior-facing. The seal area may be greater than 0 mm and less thanapproximately 3.5 mm in maximum dimension.

From the foregoing, it will be seen that the disclosed features are welladapted to attain all the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

Since many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

What is claimed is:
 1. A mold for forming a pressurized fluid chamber,the mold comprising: a generally planar region; a dome-shaped depressionwithin the planar region, the dome-shaped depression comprising anopening to an exterior of the mold; a compression area bounding thegenerally planar region and protruding upwardly from a front surface ofthe mold such that the compression area is raised relative to thegenerally planar region; and a channel through at least two of thegenerally planar region, the dome-shaped depression, and the compressionarea, the channel in fluid communication with an area of the mold beyondthe compression area.
 2. The mold of claim 1, wherein the channel isdisposed through all three of the generally planar region, thedome-shaped depression, and the compression area.
 3. The mold of claim1, wherein the opening comprises an oculus that opens through arear-facing side of the mold to the exterior of the mold.
 4. The mold ofclaim 3, wherein the dome-shaped depression has a diameter between 4 mmand 8 mm.
 5. The mold of claim 3, wherein the oculus has a maximumdiameter between 2.7 mm and 5.5 mm.
 6. A system for inflating athermoformed fluid chamber, the system comprising: a mold, the moldcomprising a cavity forming plate and a cap plate, the cavity formingplate comprising: a generally planar region; a dome-shaped depressionwithin the planar region, the dome-shaped depression comprising anopening to an exterior of the mold; a compression area bounding thegenerally planar region and protruding upwardly from a front surface ofthe mold such that the compression area is raised relative to thegenerally planar region; a channel through at least two of the generallyplanar region, the dome-shaped depression, and the compression area, thechannel in fluid communication with an area of the mold beyond thecompression area; and one or more venting apertures outside thecompression area; the cap plate comprising: an aperture in fluidcommunication with the channel in the cavity forming plate; raisedregions corresponding to the one or more venting apertures in the cavityforming plate and protruding upwardly from a front surface of the capplate; and one or more pressure channels, the pressure channels in fluidcommunication with the channel in the cavity forming plate.
 7. Thesystem of claim 6, further comprising a seaming apparatus.
 8. The systemof any of claim 6, wherein the one or more pressure channels canalternately deliver vacuum and positive pressure.
 9. The system of anyof claim 6, wherein the system further comprises an air pressuredelivery tube.
 10. The system of claim 9, wherein the air pressuredelivery tube is integral to a seaming apparatus.
 11. The system ofclaim 6 further comprising a seaming apparatus, wherein the seamingapparatus employs energy selected from heat, ultrasound, and radiofrequency.
 12. The system of claim 6, wherein the opening is concaverelative to the generally planar region.
 13. The system of claim 6,wherein the opening is round.